I use qBittorrent for torrent downloads, and since I have a slowish connection and tend to download large files I want it to be running all the time while I'm logged in (BTW why do all the BT clients require you to log in? another "benefit" of GUIs I guess). Anyway, I configured Autostart to fire up QBT on login, but I also use "save session" in KDE. Guess what: I get two instances of QBT running. Now the odd thing is that QBT is a "single instance" app. It's supposed to detect a running copy and not start another one. However the way it does this is by looking for a /tmp/qBittorrent-<uid> file. This actually works. There is a (single) file there when the two instances are running, and if I try to start a third one from the Shell it quite rightly refuses. I disabled the instance in Autostart and re-logged in. Now I get one instance, and one file in /tmp. So problem solved, but why? Is it possible that the first (Autostart) instance of QBT creates the file, and something in the KDE startup sequence deletes it before the second (saved session) instance fires up? I can't think of another explanation, but IMHO this is Bad. poc
